code: def run(self):
      ...
  
file_path: pytorch-lightning/docs/source-app/code_samples/quickstart/app_comp.py
imports: from lightning.app import LightningFlow, LightningApp
  from lightning.app.testing import EmptyFlow, EmptyWork
label_desc: Use image node_id 2 for calling the FlowA obj's underlying member method code with example usage: obj.run() without return types